1. Field of the Invention
The present invention relates in general to control of navigation lights aboard a sailing vessel, and specifically to improving the method of selecting the desired correct combination.
2. Prior Art
The Deck-level Running Lights (DRL) are a group of lights which must be displayed in conjunction and are typically controlled by a single switch. The Steaming Light, Anchor Light, and Masthead Running Lights are individual lights. The Steaming Light (SL) is displayed only in conjunction with the Deck-level Running Lights and no others when the vessel is being operated under auxiliary (motor) power. The Anchor Light (AL) must not be displayed in conjunction with any other light. The Masthead Running Lights are used only when the vessel is operating under sail without auxiliary power. The Tri-color Masthead Running Light (TMRL) must not be displayed in conjunction with any other light, and the Bi-color Masthead Running Light (BMRL) must be displayed in conjunction with the Deck-level Running Lights and no others.
Under existing wiring practice, an auxiliary (motorized) sailing vessel equipped with a fixed (permanently-mounted) Anchor Light and a Masthead Running Light would have (among others) four light switches on the electric panel: Deck-level Running Lights, Steaming Light, Anchor Light, and Masthead Running Light. The Anchor Light and the Masthead Running Light, while retaining their separate functions, might be combined in a single fixture and be controlled by a single switch to eliminate the possibility of both being lit at the same time. If the vessel is wired with four on-off switches, there would be a total of sixteen possible switch settings, only five of which result in a proper display of lights it has not been a common practice for a vessel to be equipped with both Tri-color and Bi-color Masthead Running Lights, and the author is unaware of any manufacturer offering a fixture combining both Tri-color and Bi-color Masthead Running Lights. If the above vessel were equipped with both types of masthead light and wired with five on-off switches, there would be a total of thirty-two possible combinations, of which six are proper and twenty-six are improper.
A two-wire installation of the Anchor Light and the Masthead Running Light is often effected by using a pair of diodes at the masthead to eliminate the weight of a common mast return wire running the length of the mast. If the vessel has a steaming light and/or a foredeck light and/or spreader lights, the advantage over using a common mast return is reduced to the elimination of a single strand of wire in the top half of the mast. If a masthead (emergency) strobe light is included, there is no advantage. Use of a common mast return also eliminates two possible points of failure--the diodes--from the masthead. The possibility remains for a Tri-color Masthead Running Light or Anchor Light to be displayed improperly in combination with Deck-level Running Lights and/or Steaming Light.
At least one yacht manufacturer (Cabo Rico) has attempted to simplify the light controls by offering a single switch with positions which select Sailing (Tri-color Masthead Running Light), Off, and Power (Steaming Light and Deck-level Running Lights) modes. Several purchasers of this system have requested addition of a switch which disables the Steaming Light to allow use of the Deck-Level Running Lights while sailing. Because the Deck-level Running Lights and the Steaming Light are wired as a single circuit, this switch is located at the base of the mast. Due to location of the added switch and the Sailing-Off-Power switches in different places, an operator might select the Power setting and forget that the Steaming Light had previously been disabled. A Bi-color Masthead Running Light could be added to this arrangement by replacing the Steaming Light switch at the base of the mast with a single-pole double-throw switch (with center off) to select the SL or the BMRL. The location of the switch would still be awkward, and the Anchor Light is not included in this system.
It is possible under prior art to place all navigation lights under control of a microprocessor programed to allow only proper combinations of lights. The author is unaware of such a system having been implemented on private recreational vessels, but recognizes the possible advantages for larger commercial vessels.